Spinal deformity surgery in patients for whom blood transfusion is not an option: a single-center experience.

OBJECTIVE: Spinal deformity surgery is associated with significant blood loss, often requiring the transfusion of blood and/or blood products. For patients declining blood or blood products, even in the face of life-threatening blood loss, spinal deformity surgery has been associated with high rates of morbidity and mortality. For these reasons, patients for whom blood transfusion is not an option have historically been denied spinal deformity surgery. METHODS: The authors retrospectively reviewed a prospectively collected data set. All patients declining blood transfusion who underwent spinal deformity surgery at a single institution between January 2002 and September 2021 were identified. Demographics collected included age, sex, diagnosis, details of any prior surgery, and medical comorbidities. Perioperative variables included levels decompressed and instrumented, estimated blood loss, blood conservation techniques used, length of surgery, length of hospital stay, and complications from surgery. Radiographic measurements included, where appropriate, sagittal vertical axis correction, Cobb angle correction, and regional angular correction. RESULTS: Spinal deformity surgery was performed in 31 patients (18 male, 13 female) over 37 admissions. The median age at surgery was 41.2 years (range 10.9-70.1 years), and 64.5% had significant medical comorbidities. A median of 9 levels (range 5-16 levels) were instrumented per surgery, and the median estimated blood loss was 800 mL (range 200-3000 mL). Posterior column osteotomies were performed in all surgeries, and pedicle subtraction osteotomies in 6 cases. Multiple blood conservation techniques were used in all patients. Preoperative erythropoietin was administered prior to 23 surgeries, intraoperative cell salvage was used in all, acute normovolemic hemodilution was performed in 20, and perioperative administration of antifibrinolytic agents was performed in 28 surgeries. No allogenic blood transfusions were administered. Surgery was staged intentionally in 5 cases, and there was 1 unintended staging due to intraoperative blood loss from a vascular injury. There was 1 readmission for a pulmonary embolus. There were 2 minor postoperative complications. The median length of stay was 6 days (range 3-28 days). Deformity correction and the goals of surgery were achieved in all patients. Two patients underwent revision surgery during the follow-up period: one for pseudarthrosis and the other for proximal junctional kyphosis. CONCLUSIONS: With proper preoperative planning and judicious use of blood conservation techniques, spinal deformity surgery may be performed safely in patients for whom blood transfusion is not an option. The same techniques can be applied widely to the general population in order to minimize blood loss and the need for allogeneic blood transfusion.

Utility of intraoperative electromyography in placing C7 pedicle screws.

OBJECTIVE: The C7 vertebral body is morphometrically unique; it represents the transition from the subaxial cervical spine to the upper thoracic spine. It has larger pedicles but relatively small lateral masses compared to other levels of the subaxial cervical spine. Although the biomechanical properties of C7 pedicle screws are superior to those of lateral mass screws, they are rarely placed due to increased risk of neurological injury. Although pedicle screw stimulation has been shown to be safe and effective in determining satisfactory screw placement in the thoracolumbar spine, there are few studies determining its utility in the cervical spine. Thus, the purpose of this study was to determine the feasibility, clinical reliability, and threshold characteristics of intraoperative evoked electromyographic (EMG) stimulation in determining satisfactory pedicle screw placement at C7. METHODS: The authors retrospectively reviewed a prospectively collected data set. All adult patients who underwent posterior cervical decompression and fusion with placement of C7 pedicle screws at the authors' institution between January 2015 and March 2019 were identified. Demographic, clinical, neurophysiological, operative, and radiographic data were gathered. All patients underwent postoperative CT scanning, and the position of C7 pedicle screws was compared to intraoperative neurophysiological data. RESULTS: Fifty-one consecutive C7 pedicle screws were stimulated and recorded intraoperatively in 25 consecutive patients. Based on EMG findings, 1 patient underwent intraoperative repositioning of a C7 pedicle screw, and 1 underwent removal of a C7 pedicle screw. CT scans demonstrated ideal placement of the C7 pedicle screw in 40 of 43 instances in which EMG stimulation thresholds were > 15 mA. In the remaining 3 cases the trajectories were suboptimal but safe. When the screw stimulation thresholds were between 11 and 15 mA, 5 of 6 screws were suboptimal but safe, and in 1 instance was potentially dangerous. In instances in which the screw stimulated at thresholds ≤ 10 mA, all trajectories were potentially dangerous with neural compression. CONCLUSIONS: Ideal C7 pedicle screw position strongly correlated with EMG stimulation thresholds > 15 mA. In instances, in which the screw stimulates at values between 11 and 15 mA, screw trajectory exploration is recommended. Screws with thresholds ≤ 10 mA should always be explored, and possibly repositioned or removed. In conjunction with other techniques, EMG threshold testing is a useful and safe modality in determining appropriate C7 pedicle screw placement.

Retreatment of trigeminal neuralgia with Gamma Knife radiosurgery: is there an appropriate cumulative dose? Clinical article.

OBJECT: Trigeminal neuralgia (TN) is a disorder of the trigeminal nerve that results in intense episodic pain. Primary treatment with Gamma Knife surgery (GKS) is well established; however, a significant number of patients experience recurrence of TN over time. Repeat GKS can be performed, but the retreatment dose has not been well established. In this study, the authors present their institutional retreatment results and compare them with other series. METHODS: Between December 2003 and January 2006, 28 patients were treated at Tufts Medical Center with repeat GKS for recurrence of TN. All patients had been initially treated with GKS at this institution, and only those with significant pain improvement were offered retreatment. The maximum dose was prescribed using a single isocenter; the 4-mm collimator was used. The initial median GKS dose was 80 Gy, the median retreatment dose was 45 Gy, and the median cumulative dose was 125 Gy. The median time between GKS procedures was 18.1 months. Facial pain outcomes were defined using the Marseille scale. Excellent outcome was defined as no pain (with or without medications), and good outcome was defined as > 50% pain relief. Toxicity was categorized as none, mild, or bothersome. The median clinical follow-up after the second GKS was 19.7 months. Our clinical outcomes were compared with 8 previously reported retreatment series (including 1 abstract), both for rate of pain control and for rate of complications. RESULTS: Outcomes after the second GKS were excellent in 29% (8 patients), good in 32% (9), and poor in 39% (11). Four patients (14%) experienced no improvement after repeat GKS. Eight patients (29%) experienced new trigeminal nerve dysfunction, including numbness (11%), paresthesia (14%), dysesthesia (4%), taste alteration (11%), and bite weakness (4%). None of these were bothersome. No patient developed corneal numbness. Univariate analysis failed to reveal any significant predictors of pain control or complications. Seven published peer-reviewed retreatment series and the authors' data (total 215 patients) were analyzed. There was a cumulative dose-response relationship for both pain control (p = 0.04) and new trigeminal dysfunction (p = 0.08). Successful pain control was strongly correlated with development of new dysfunction (p = 0.02). A cumulative dose > 130 Gy was more likely to result in successful (> 50%) pain control, but was also more likely (> 20%) to result in development of new dysfunction. CONCLUSIONS: Successful retreatment of patients in whom the initial GKS treatment fails is feasible. Patients who respond initially may be at a higher risk of retreatment-related complications. There appears to be a dose-response relationship for both pain control and development of new side effects. It is important to counsel and treat patients individually based on this dose-response relationship.

Complications of Poor Cervical Alignment in Patients Undergoing Posterior Cervicothoracic Laminectomy and Fusion.

OBJECTIVE: This study sought to determine whether a relationship exists between caudal instrumented level and revision rates, neck disability index scores, and cervical alignment in patients undergoing multilevel posterior cervical fusion. METHODS: This study examined a dataset of all patients undergoing posterior cervical decompression and fusion at ≥3 levels, terminating between C4 and T4, between January 2010 and December 2015, with at least 12 months of clinical follow-up. Patients were separated into cohorts based on caudal level of the fusion: C6 (or more cranial), C7, T1, or T2 (or more caudal). Revision rate, neck disability index score, sagittal vertical axis, T1 slope, and cervical lordosis were recorded. Linear regression and multivariate analysis were performed to identify independent predictors of patient outcomes and disparities between ending constructs in the cervical and the thoracic spine. RESULTS: The overall revision rate was 10.8% (n = 24). No statistically significant difference in the revision rate was identified between fusions terminating at C6 or cranial, C7, T1, or T2 and caudal (P = 0.74). Revision correlated strongly with increased sagittal vertical axis (P = 0.002) and T1 slope (P = 0.04). Increased neck disability index score correlated with revision rate (P = 0.01), cervical kyphosis (P < 0.001), and increased sagittal vertical axis (P = 0.04). CONCLUSIONS: This study suggests that constructs terminating in the proximal thoracic spine have similar revision rates, postoperative neck disability index scores, and radiographic measurements as those terminating in the cervical spine. Poor cervical alignment, as evidenced by increased sagittal vertical axis, cervical kyphosis and T1 slope, predicts need for revision and of poorer clinical outcomes.

The case for T2 pedicle subtraction osteotomy in the surgical treatment of rigid cervicothoracic deformity.

OBJECTIVE: Rigid cervicothoracic kyphotic deformity (CTKD) remains a difficult pathology to treat, especially in the setting of prior cervical instrumentation and fusion. CTKD may result in chronic neck pain, difficulty maintaining horizontal gaze, and myelopathy. Prior studies have advocated for the use of C7 or T1 pedicle subtraction osteotomies (PSOs). However, these surgeries are fraught with danger and, most significantly, place the C7, C8, and/or T1 nerve roots at risk. METHODS: The authors retrospectively reviewed their experience with performing T2 PSO for the correction of rigid CTKD. Demographics collected included age, sex, details of prior cervical surgery, and coexisting conditions. Perioperative variables included levels decompressed, levels instrumented, estimated blood loss, length of surgery, length of stay, complications from surgery, and length of follow-up. Radiographic measurements included C2-7 sagittal vertical axis (SVA) correction, and changes in the cervicothoracic Cobb angle, lumbar lordosis, and C2-S1 SVA. RESULTS: Four male patients were identified (age range 55-72 years). Three patients had undergone prior posterior cervical laminectomy and instrumented fusion and developed postsurgical kyphosis. All patients underwent T2 PSO: 2 patients received instrumentation at C2-T4, and 2 patients received instrumentation at C2-T5. The median C2-7 SVA correction was 3.85 cm (range 2.9-5.3 cm). The sagittal Cobb angle correction ranged from 27.8° to 37.6°. Notably, there were no neurological complications. CONCLUSIONS: T2 PSO is a powerful correction technique for the treatment of rigid CTKD. Compared with C7 or T1 PSO, there is decreased risk of injury to intrinsic hand muscle innervators, and there is virtually no risk of vertebral artery injury. Laminectomy may also be safer, as there is less (or no) scar tissue from prior surgeries. Correction at this distal level may allow for a greater sagittal correction. The authors are optimistic that these findings will be corroborated in larger cohorts examining this challenging clinical entity.

Risk factors for progressive spinal deformity following resection of intramedullary spinal cord tumors in children: an analysis of 161 consecutive cases.

OBJECT: Gross-total resection of pediatric intramedullary spinal cord tumors (IMSCTs) can be achieved in the majority of cases, with preservation of long-term neurological function. However, progressive spinal deformity requiring subsequent fusion occurs in many cases. It remains unknown which subgroups of patients have the greatest risk for progressive spinal deformity. METHODS: Data for 161 patients undergoing resection of IMSCTs at a single institution were retrospectively collected and analyzed with regard to the development of progressive spinal deformity requiring fusion and patient functional status (based on the modified McCormick Scale [mMS] and Karnofsky Performance Scale [KPS]) by conducting telephone interviews corroborated by medical records. The independent association of all clinical, radiographic, and operative variables to subsequent progressive spinal deformity was assessed using multivariate logistic regression analysis. RESULTS: Patients were a mean of 8.6 +/- 5.7 years old at the time of surgery. The tumor spanned a mean of six +/- three spinal levels. Preoperative scoliotic deformity was present in 56 cases (35%). Seventy-six patients (47%) had undergone a previous biopsy procedure, and 28 (17%) a prior resection. Gross-total resection (> 95%) was achieved in 122 cases (76%). A median of 9 years (range 1-21) after surgery, progressive spinal deformity requiring fusion developed in 43 patients (27%). The median functional scores at the last follow-up were worse in patients who required fusion compared with those who did not (mMS: 3 compared with 2, p = 0.006; KPS: 80 compared with 90, p = 0.04) despite similar mMS scores between the groups at 3 months postoperatively. An age less than 13 years, preoperative scoliotic deformity (Cobb angle > 10 degrees), involvement of the thoracolumbar junction, and tumor-associated syrinx independently increased the odds of a postoperative progressive deformity requiring fusion 4.4-, 3.2-, 2.6-, and 3.4-fold, respectively (p < 0.05). Each subsequent resection increased the odds of a progressive deformity 1.8-fold (p < 0.05). Symptoms lasting less than 1 month before resection decreased the odds of spinal deformity requiring fusion ninefold (p < 0.05). CONCLUSIONS: Progressive spinal deformity requiring fusion occurred in 27% of children undergoing resection of an IMSCT and was associated with a decreased functional status. Preoperative scoliotic deformity, an increasing number of resections, an age less than 13 years, tumor-associated syrinx, and surgery spanning the thoracolumbar junction increased the risk for progressive spinal deformity. Patients possessing one or more of these characteristics should be monitored closely for progressive spinal deformity following surgery.

Molecular response of human glioblastoma multiforme cells to ionizing radiation: cell cycle arrest, modulation of the expression of cyclin-dependent kinase inhibitors, and autophagy.

OBJECT: Ionizing radiation is the gold-standard adjuvant treatment for glioblastoma multiforme (GBM), the most aggressive primary brain tumor. The mechanisms underlying neoplastic glial cell growth inhibition after administration of ionizing radiation, however, remain largely unknown. In this report, the authors characterize the response of GBM cells to ionizing radiation and elucidate factors that correlate with the radiosensitivity of these tumors. METHODS: Six human GBM cell lines were subjected to increasing doses of radiation. Each demonstrated a dose-dependent suppression of cell proliferation. In the most radiosensitive cell line, the authors demonstrated a transient increase in the expression of the cyclin-dependent kinase inhibitors (CDKIs) p21 and p27, which corresponded with a G1 cell-cycle arrest. In contrast, the most radioresistant cell line demonstrated a decrease in p21 and p27 expression levels, which correlated with a failure to arrest. Apoptosis did not occur in any cell line following irradiation. Instead, autophagic cell changes were observed following administration of radiation, regardless of the relative radiosensitivity of the cell line. CONCLUSIONS: These findings elucidate some of the molecular responses of GBMs to irradiation and suggest novel targets for future therapy.

En bloc spondylectomy for spinal metastases: a review of techniques.

OBJECT: Spinal metastases are prevalent in the population of patients with cancer. Effective cancer therapy must incorporate treatment strategies for these lesions. Increasingly, surgery is being recognized as an effective treatment modality both for the patient's quality of life and potential oncological cure. En bloc spondylectomy is the surgical procedure of choice to obtain these goals. The purpose of this study was to examine critically the rationale, indications, and outcomes of en bloc spondylectomy for spinal metastases. METHODS: Outcomes in the authors' series of patients who underwent en bloc spondylectomy for spinal metastases are critically analyzed. The rationale and indications for this procedure are discussed. The Weinstein, Boriani, and Biagini surgical staging system for spinal tumors is described. A review of the literature is performed to examine further the rationale underlying this aggressive surgical approach to metastatic spinal disease. CONCLUSIONS: En bloc spondylectomy is the treatment of choice for solitary and oligometastatic spinal metastaseswith biologically favorable histological findings. In appropriately selected patients, neurological outcome, pain control, and oncological control are significantly better after en bloc spondylectomy compared with radiation therapy. Oncological outcomes also exceed those of intralesional techniques. The Weinstein, Boriani, and Biagini surgical staging system provides a standard with which to plan surgical approaches and to compare surgical outcomes.

Local control and results of Leksell Gamma Knife therapy for the treatment of uveal melanoma.

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of Leksell Gamma Knife stereotactic radio-surgery (Elekta, Stockholm, Sweden) with respect to local tumor control, visual acuity, and radiation side effects for uveal melanoma. PATIENTS AND METHODS: Retrospective, non-comparative case series of 23 patients with uveal melanoma treated with Gamma Knife stereotactic radiosurgery at Tufts Medical Center from 2000 to 2012. Patients received single-fraction stereotactic radiation therapy of 20-25 gray (Gy) (mean: 21.7 Gy), primarily at the 50% isodose line. Follow-up was 4 to 121 months (median: 41.5 months). Main outcome measures included local tumor control, metastasis, visual acuity, and complications of therapy. RESULTS: In 21 of 23 patients (91%), local control was achieved with a single session of Gamma Knife therapy. Both patients who did not have local control, as well as a third patient (three of 23, 13%) developed liver metastases. Visual acuity was 20/200 or better in eight of 23 patients (35%) at last follow-up. Radiation side effects severe enough to cause vision loss were present in 14 of 23 patients (61%). CONCLUSION: Gamma Knife therapy may be an effective alternative to enucleation in patients with uveal melanoma who are deemed less satisfactory candidates for brachytherapy or wish to avoid surgery.

Transpedicular N-butyl cyanoacrylate-mediated percutaneous embolization of symptomatic vertebral hemangiomas.

OBJECT: The resection of spinal hemangiomas is often challenging because of characteristic high-volume and potentially prohibitive intraoperative blood loss. Although transarterial embolization can mitigate this risk, it can be suboptimal when tumor arterial supply is diffuse or poorly defined. The authors present their experience in the use of preoperative percutaneous direct injection of spinal hemangiomas with N-butyl cyanoacrylate (NBCA) as an effective preoperative adjunct that may reduce operative blood loss and facilitate resection of these vascular tumors. METHODS: Four patients with symptomatic spinal hemangiomas were treated using percutaneous transpedicular direct NBCA-Lipiodol injection; 2 patients had undergone prior spinal angiography, with suboptimal transarterial embolization in 1. Each patient underwent percutaneous bilateral transpedicular NBCA-assisted tumor embolization prior to resection. Retrospective analysis of operative times, blood loss, and clinical data is presented. RESULTS: There were no complications associated with the percutaneous NBCA embolization technique. The procedure was effective at facilitating tumor removal and minimizing intraoperative blood loss, especially at the vertebral body resection stage. Improved tumor filling was achieved as the filling characteristics of dilute NBCA-Lipiodol mixture within large-channel, high-flow hemangiomas were appreciated with experience. CONCLUSIONS: Transpedicular NBCA direct-puncture embolization of spinal hemangiomas is an effective preoperative adjunct that facilitates resection of these highly vascular tumors. It is particularly useful when transarterial embolization is unsafe or suboptimal due to constraints imposed by the local angioarchitecture.

Spontaneous resolution of a Chiari malformation Type I and syrinx after supratentorial craniotomy for excision of a cavernous malformation.

The pathogenesis of Chiari malformation Type I (CM-I) and associated syringomyelia is incompletely understood. Patients often present in middle age with incidental or minimally symptomatic CM-I, whose management is controversial. One option is clinical and radiographic observation of asymptomatic and minimally symptomatic patients. The authors here present the case of a 36-year-old woman who had been monitored for 6 years for a minimally symptomatic CM-I and cervicothoracic syrinx. After 5 years of follow-up, she suffered spontaneous rupture of a cerebral cavernous malformation when she was 27 weeks pregnant. The ruptured cavernous malformation and hematoma were operatively managed via a right frontal craniotomy. Ten months after the craniotomy for resection of the ruptured cavernous malformation, follow-up MRI demonstrated resolution of the CM-I and syrinx. Few similar cases have been reported in adults. This case argues for the presence of dynamic factors in the development and maintenance of CM-I and supports the nonoperative treatment of asymptomatic and minimally symptomatic patients.

A fourth atlantoaxial joint: an initial description.

BACKGROUND CONTEXT: The presence of a supernumerary posterior atlantoaxial facet joint has not been reported in the literature. PURPOSE: To describe a patient who presented with a unilateral anomalous posterior facet joint and discuss its possible embryological origin. STUDY DESIGN/SETTING: Case report. METHODS: A 35-year-old woman presented with severe neck pain, headaches, and tingling radiating down her left arm. Radiological studies showed an anomalous right C1-C2 facet joint causing dorsal compression of the spinal cord and cord compression secondary to a C5-C6 herniated disc. The patient underwent resection of the abnormal facet via a posterior approach followed by anterior cervical discectomy and fusion at C5-C6. RESULTS: The patient reported marked improvement in her neck pain and partial improvement in her left upper extremity numbness and tingling. Postoperative radiographs showed no abnormal motion at C1-C2. CONCLUSIONS: The authors hypothesize that, in this patient, the C1 and C2 sclerotomes may have fused abnormally posteriorly, followed by the initiation of events at this site that eventually led to the formation of a morphologically normal synovial joint in an abnormal location.

Analysis of visual toxicity after gamma knife radiosurgery for treatment of choroidal melanoma: identification of multiple targets and mechanisms of toxicity.

OBJECTIVES: Identification of the targets of radiation damage after radiosurgical treatment of ocular melanoma will potentially allow for sparing of vision with improved treatment planning. MATERIALS AND METHODS: Six patients with ocular melanoma, who had useful vision before therapy, were treated with gamma knife stereotactic radiosurgery with curative intent. Dosimetric analysis of functional targets of radiation damage including the fovea, optic nerve, lens, and iris was carried out. Serial testing of visual acuity and fundoscopic examination were carried out after treatment. RESULTS: Visual sparing was achieved in 3 of 6 patients at last followup with a median follow-up of 2 years. The causes of loss of vision in those patients who lost useful vision were retinal detachment, neovascular glaucoma, and optic neuropathy. CONCLUSIONS: Preradiosurgical size and location are likely predictors of posttreatment visual outcomes.

Outcomes following single-treatment Gamma Knife surgery for trigeminal neuralgia with a minimum 3-year follow-up.

OBJECT: Gamma Knife surgery (GKS) has been shown to be effective in treating trigeminal neuralgia (TN). Existing studies have demonstrated success rates of 69.1-85% with median follow-up intervals of 19-60 months. However, series with uniform long-term follow-up data for all patients have been lacking. In the present study the authors examined outcomes in a series of patients with TN who underwent a single GKS treatment followed by a minimum follow-up of 36 months. They used a clinical scale that simplifies the reporting of outcome data for patients with TN. METHODS: Fifty-three consecutive patients with typical, intractable TN received a median maximum radiation dose of 80 Gy applied with a single 4-mm isocenter to the affected trigeminal nerve. Follow-up data were obtained by clinical examination and questionnaire. Outcome results were categorized into the following classes (in order of decreasing success): Class 1A, complete pain relief without medications; 1B, complete pain relief with either a decrease or no change in medications; 1C, > or = 50% pain relief without medications; 1D, > or = 50% pain relief with either a decrease or no change in medications; and Class 2, < 50% pain relief and/or increase in medications. Patients with Class 1A-1D outcome (equivalent to Barrow Neurological Institute Grades I-IIIb) were considered to have a good treatment outcome, whereas in patients with Class 2 outcome (equivalent to Barrow Neurological Institute Grades IV and V) treatment was considered to have failed. RESULTS: A good treatment outcome from initial GKS was achieved in 31 (58.5%) patients for whom the mean follow-up period was 48 months (range 36-66 months). Outcomes at last follow-up were reflected by class status: Class 1A, 32.1% of patients; 1B, 1.9%; 1C, 3.8%; 1D, 20.8%; and Class 2, 41.5%. Statistical analysis showed no difference in outcomes between patients previously treated with microvascular decompression or rhizotomy compared with patients with no previous surgical treatments. Thirty-six percent of patients reported some degree of posttreatment facial numbness. Anesthesia dolorosa did not develop in any patient. CONCLUSIONS: Despite a time-dependent deterioration in the success rate of GKS for medically intractable TN, the authors' study showed that > 50% of patients can be expected to have a good outcome based on their scoring system, with approximately 33% having an ideal outcome (pain free with no need for medications). Long-term data, as those presented here, are important when counseling patients on their treatment options.

Dose de-escalation with gamma knife radiosurgery in the treatment of choroidal melanoma.

PURPOSE: Single-fraction targeted radiation therapy delivered by the Leksell Gamma Knife system is a minimally invasive treatment option for choroidal melanoma that has been used as an alternative to enucleation, proton beam therapy, or brachytherapy. Previously reported Gamma Knife series involved the treatment of choroidal melanomas with a dose of 40 to 50 Gy at the tumor margin. We report our institutional experience using a significantly lower dose. METHODS AND MATERIALS: Fourteen patients with choroidal melanoma were treated with the Leksell Gamma Knife at our institution over a 7-year period. The treatment and clinical data were analyzed in a retrospective fashion after a mean follow-up of 32.2 months. RESULTS: The mean dose to the tumor margin was 22.2 +/- 2.4 Gy (range, 20- 25 Gy). Mean treated tumor volume was 1.1 +/- 1.2 cc. Local control was achieved in 13 cases (93%). In 1 patient both intraocular spread and distant metastatic disease developed after treatment. Visual function of the affected eye was preserved in 5 patients (36%) at latest follow-up, in 9 patients (64%) visual loss ensued. Mild to moderate radiation toxicity developed in 8 patients. CONCLUSIONS: Choroidal melanoma can be safely and effectively treated using Leksell Gamma Knife stereotactic radiosurgery with a marginal dose of less than 25 Gy.

Resection of intramedullary spinal cord tumors in children: assessment of long-term motor and sensory deficits.

OBJECT: With modern surgical advances, radical resection of pediatric intramedullary spinal cord tumors (IMSCTs) can be expected to preserve long-term neurological function. Nevertheless, postoperative neurological decline is not uncommon after surgery, and many patients continue to experience long-term dysesthetic symptoms. Preoperative predictors of postoperative neurological decline and sensory syndromes have not been investigated and may serve as a guide for surgical risk stratification. METHODS: Neurological function (as determined using the modified McCormick Scale [mMS]) preoperatively, postoperatively, and 3 months after surgery was retrospectively recorded from patient charts in 164 consecutive patients undergoing resection of IMSCTs. A median 4 years (interquartile range [IQR] 1-8 years) after surgery, long-term motor and sensory symptoms were assessed by telephone interviews and corroborated by subsequent medical visits in 120 available patients. This long-term assessment was retrospectively reviewed for the purposes of this study. The authors reviewed this series to assess long-term motor, sensory, and urinary outcomes and to determine independent risk factors of postoperative neurological decline and long-term sensory dysfunction. RESULTS: Patients were 8.6 +/- 5.7 years old and presented with a median mMS of 2 (IQR 2-4). Three months after surgery, 38 patients (23%) continued to experience decreased neurological function (1 mMS point) incurred perioperatively. Increasing age (p = 0.028), unilateral symptoms (p = 0.046), and urinary dysfunction at presentation (p = 0.004) independently predicted persistent 3-month perioperative decline. At long-term follow-up (median 4 years), 39 (33%) exhibited improvements in their mMS scores, 13 (30%) had improvement in their urinary dysfunction, and 27 (30%) had resolution of their dysesthesias. Seventy-eight patients (65%) experienced long-term dysesthetic symptoms. Increasing age (p = 0.024), preoperative symptom duration > 12 months (p = 0.027), and worsened postoperative mMS score at hospital discharge (p = 0.013) independently increased the risk of long-term dysesthesias. CONCLUSIONS: In the authors' experience, nearly one third of patients may experience improvement in motor, sensory, and urinary dysfunction years after IMSCT resection, whereas the majority will continue to experience long-term dysesthetic symptoms. Improvement in motor deficits preceded improvement in sensory syndromes, and urinary dysfunction typically resolved much longer after surgery. The risk of persistent perioperative motor decline was increased with older age, unilateral symptoms, preoperative urinary symptoms, and less severe preoperative neurological deficit. The risk of long-term dysesthesias was increased with older age, increased duration of symptoms prior to resection, and greater postoperative neurological deficit.

Spinal deformity after resection of cervical intramedullary spinal cord tumors in children.

OBJECTIVE: Progressive spinal deformity after cervical intramedullary spinal cord tumor (IMSCT) resection requiring subsequent fusion occurs in many cases among pediatric patients. It remains unknown which subgroups of patients represent the greatest risk for progressive spinal deformity. MATERIALS AND METHODS: The data for 58 patients undergoing surgical resection of cervical IMSCT at a single institution were retrospectively collected and analyzed for development of progressive spinal deformity requiring fusion. The association of all clinical, radiographic, and operative variables to subsequent progressive spinal deformity as a function of time was assessed via Kaplan-Meier plots and Log-rank and Cox analyses. RESULTS: Mean age at the time of surgery was 11 +/- 6 years. Eleven (19%) patients required subsequent fusion for progressive spinal deformity at a median [interquartile range (IQR)] of 4 (2-6) years after IMSCT resection. Five (36%) of 14 patients with preoperative scoliosis or loss of lordosis developed postoperative progressive spinal deformity compared to only 6 (13%) of 44 patients with normal preoperative sagittal and coronal balance, p = 0.06. Patients <13 years of age were more than three times more likely to develop postoperative progressive deformity, p = 0.05. Decompression spanning both the axial cervical spine (C1-C2) and the cervico-thoracic junction (C7-T1) increased the risk for progressive spinal deformity fourfold, p = 0.04. Number of spinal levels decompressed, revision surgery, radiotherapy, involvement of C1-C2 or C7-T1 alone in the decompression, or any other recorded variables were not associated with progressive postoperative spinal deformity. CONCLUSION: Patients possessing one or more of these characteristics should be monitored closely for progressive spinal deformity after surgery.

Incidence of spinal deformity after resection of intramedullary spinal cord tumors in children who underwent laminectomy compared with laminoplasty.

OBJECT: Gross-total resection of pediatric intramedullary spinal cord tumor (IMSCT) can be achieved in the majority of cases while preserving long-term neurological function. Nevertheless, postoperative progressive spinal deformity often complicates functional outcome years after surgery. The authors set out to determine whether laminoplasty in comparison with laminectomy has reduced the incidence of subsequent spinal deformity requiring fusion after IMSCT resection at their institution. METHODS: The first 144 consecutive patients undergoing resection of IMSCTs at a single institution underwent laminectomy with preservation of facet joints. The next 20 consecutive patients presenting for resection of IMSCTs underwent osteoplastic laminotomy regardless of patient or tumor characteristics. All patients were followed up with telephone interviews corroborated by medical records for the following outcomes: 1) neurological and functional status (modified McCormick Scale [MMS] score and Karnofsky Performance Scale [KPS] score); and 2) development of progressive spinal deformity requiring fusion. The incidence of progressive spinal deformity and the long-term neurological function were compared between the laminectomy and osteoplastic laminotomy cohorts. The means are expressed +/- the standard deviation. RESULTS: Overall, the patients' mean age was 8.6 +/- 5 years, and they presented with median MMS scores of 2 (interquartile range [IQR] 2-4). A > 95% resection was achieved in 125 cases (76%). There were no differences (p > 0.10) between patients treated with osteoplastic laminotomy and those treated with laminectomy in terms of the following characteristics: age; sex; duration of symptoms; location of tumor; incidence of preoperative scoliosis (Cobb angle > 10 degrees : 7 [35%] with laminoplasty compared with 49 [34%] with laminectomy); involvement of the cervicothoracic junction (7 [35%] compared with 57 [40%]); thoracolumbar junction (4 [20%] compared with 36 [25%]); tumor size; extent of resection; radiation therapy; histopathological findings; or mean operative spinal levels (7.5 +/- 2 compared with 7.5 +/- 3). Nevertheless, patients who underwent osteoplastic laminotomy had better median preoperative MMS scores than those treated with laminectomy (2 [IQR 2-2] compared with 2 [IQR 2-4]; p = 0.04). A median of 3.5 years (IQR 1-7 years) after surgery, only 1 patient (5%) in the osteoplastic laminotomy cohort required fusion for progressive spinal deformity, compared with 43 (30%) in the laminectomy cohort (p = 0.027). Adjusting for the inter-cohort difference in preoperative MMS scores, osteoplastic laminotomy was associated with a 7-fold reduction in the odds of subsequent fusion for progressive spinal deformity (odds ratio 0.13, 95% confidence interval 0.02-1.00; p = 0.05). The median MMS and KPS scores were similar between patients who underwent osteoplastic laminotomy and those in whom laminectomy was performed (MMS Score 2 [IQR 2-3] for laminotomy compared with 2 [IQR 2-4] for laminectomy, p = 0.54; KPS Score 90 [IQR 70-100] for laminotomy compared with 90 [IQR 80-90] for laminectomy, p = 0.545) at a median of 3.5 years after surgery. CONCLUSIONS: In the authors' experience, osteoplastic laminotomy for the resection of IMSCT in children was associated with a decreased incidence of progressive spinal deformity requiring fusion but did not affect long-term functional outcome. Laminoplasty used for pediatric IMSCT resection may decrease the incidence of progressive spinal deformity requiring subsequent spinal stabilization in some patients.